Creating a data layer node from Node-RED

I am running a Virtual Control and a sample PLC application which creates a simple up-counter i. I am able to read and write the data layer node associated with the counter from Node-RED using the "Data layer request" Node-RED module (version 1.2.1). The path to the variable is "/plc/app/Application/sym/PLC_PRG/i".

My problems start when I want to create/register a brand new data layer node. It seems that for any path that I choose I get a DL_INVALID_ADDRESS error, for example with this message going to the "Data layer request" node:

{ method: "CREATE", path: "designer/xyz", payload: { type: 'int16', value: 1 } }

I am not sure if this functionality is not supported by the Node-RED data layer request module, or if I am doing something wrong. It seems that it is possible to create data layer nodes, at least judging by an example in the C++ SDK. The example registers a node in "myData/myFlatbuffer", for instance.

Any help or pointers would be highly appreciated,

Pablo